This invention relates to a miniature switch and, more particularly, to a miniature electric switch having a self-alignment type movable contactor.
A principle portion of a conventional miniature switch shown in FIG. 1 includes an actuator block 1 operated by a toggle lever (not shown), a clip-shaped movable contactor 2 consisting of a resilient metal plate mounted in the actuator block 1, and a stationary terminal 3 with which the movable contactor 2 makes and breaks contact. The lower surface of the actuator block 1 is formed to include a rectangular recess 1-1, and the clip-shaped movable contactor 2 includes a projection 2-1 corresponding to the rectangular recess 1-1. To mount the movable contactor 2 in the actuator 1, the projection 2-1 is press-fitted into the recess 1-1 from the lower side of the actuator block 1 to engage the inner wall of the recess.
When the movable contactor 2 is thus mounted in the actuator block 1 by press-fitting, as shown in FIG. 1, there are occasions where the movable contactor 2 becomes detached from the actuator block 1 during operation of the switch, thus resulting in poor contact between the movable contactor 2 and stationary contact 3. On the other hand, if the fit between the movable contactor 2 and actuator block 1 is so tight that the two can be fitted together only by exerting great force, the movable contactor 2 is likely to be deformed during the press-fitting operation, and adjusting the fit between them is difficult.
In another example of the prior-art disclosed in, for example, the specification of Japanese Utility Model Publication No. 59-7702 and illustrated in FIGS. 2 and 3, a miniature slide switch includes a slider 4 the main body of which is provided with a plurality of recesses, a clip-shaped movable contactor 5 accommodated in each of the recesses, and a plurality of stationary terminals 8 implanted in an insulating base 7 fixed by a frame 6. By moving the slider 4, each movable contactor 5 is slid successively from one stationary terminal 8 to the next. With the slide switch of this type, however, the movable contactor 5 tends to become skewed and to separate from the stationary terminals 8 when the switch is operated. Preventing this from occurring necessitates means such as a slitted slide strip 9 provided on the insulating base 7. The problem with this arrangement is that achieving the proper positional alignment between the slide strip 9 and both the stationary terminals 8 and movable contactor 5 is a troublesome task. If the movable contactor 5 undergoes any positional displacement, moreover, the slider 4 no longer travels smoothly. The result is diminished operability. Furthermore, providing the slide strip 9 complicates the overall structure of the switch and naturally increases the number of component parts.